Hello I'm new player on fantasica and I fail to understand how to learn skills.I have enough luna and I'm lvl 26 ..I just can not buy skills.

You probably don't have enough Ally Points ( You gain them by using allies in quests, or allies using you in quests ). There also might be the chance you are too low of a level for that certain skill level.

Also, when asking these, please refer to the question thread which is here